AlgebraicException

Algebraic type exception.

version(none)
@safe pure static
class AlgebraicException : Exception {}

Constructors

this
this(string s)
Undocumented in source.

Examples

equality and comparison

Algebraic!(float) a, b;
static assert(a.hasFixedSize);

dbg(a.as!float);
a = 1.0f;
dbg(a.as!float);
assert(a._tix != a.Ix.init);

dbg(b.as!float);
b = 1.0f;
dbg(b.as!float);
assert(b._tix != b.Ix.init);

assert(a._tix == b._tix);
assert((cast(ubyte*)&a)[0 .. a.sizeof] == (cast(ubyte*)&b)[0 .. b.sizeof]);
assert(a == b);             // TODO: this errors with dmd master
alias C = Algebraic!(float, double);
C a = 1.0;
const C b = 2.0;
const C c = 2.0f;
const C d = 1.0f;

assert(a.commonValue == 1);
assert(b.commonValue == 2);
assert(c.commonValue == 2);
assert(d.commonValue == 1);

// nothrow comparison possible
assert(a < b);
assert(a < c);
assert(a == d);

static assert(!a.hasFixedSize);
static assert(a.allowsAssignmentFrom!float);
static assert(a.allowsAssignmentFrom!double);
static assert(!a.allowsAssignmentFrom!string);

a.clear();
assert(!a.hasValue);
assert(a.peek!float is null);
assert(a.peek!double is null);
assert(a.currentSize == 0);

aliasing traits

import std.traits : hasAliasing;
static assert(!hasAliasing!(Algebraic!(long, double)));
static assert(!hasAliasing!(Algebraic!(long, string)));
static assert(!hasAliasing!(Algebraic!(long, immutable(double)*)));
static assert(hasAliasing!(Algebraic!(long, double*)));

equality and comparison

Algebraic!(int) a, b;
static assert(a.hasFixedSize);
a = 1;
b = 1;
assert(a == b);

equality and comparison

Algebraic!(float) a, b;
static assert(a.hasFixedSize);
a = 1.0f;
b = 1.0f;
assert(a == b);

equality and comparison

Algebraic!(float, double, string) a, b;

static assert(!a.hasFixedSize);

a = 1.0f;
b = 1.0f;
assert(a == b);

a = 1.0f;
b = 2.0f;
assert(a != b);
assert(a < b);
assert(b > a);

a = "alpha";
b = "alpha";
assert(a == b);

a = "a";
b = "b";
assert(a != b);
assert(a < b);
assert(b > a);

AA keys

alias C = Algebraic!(float, double);
static assert(!C.hasFixedSize);
string[C] a;
a[C(1.0f)] = "1.0f";
a[C(2.0)] = "2.0";
assert(a[C(1.0f)] == "1.0f");
assert(a[C(2.0)] == "2.0");

verify nothrow comparisons

alias C = Algebraic!(int, float, double);
static assert(!C.hasFixedSize);
assert(C(1.0) < 2);
assert(C(1.0) < 2.0);
assert(C(1.0) < 2.0);
static assert(!__traits(compiles, { C(1.0) < 'a'; })); // cannot compare with char
static assert(!__traits(compiles, { C(1.0) < "a"; })); // cannot compare with string

TODO

// alias C = Algebraic!(int, float, double);
// alias D = Algebraic!(float, double);
// assert(C(1) < D(2.0));
// assert(C(1) < D(1.0));
// static assert(!__traits(compiles, { C(1.0) < "a"; })); // cannot compare with string

if types have CommonType comparison is nothrow @nogc

alias C = Algebraic!(short, int, long, float, double);
static assert(!C.hasFixedSize);
assert(C(1) != C(2.0));
assert(C(1) == C(1.0));

if types have CommonType then comparison is nothrow @nogc

alias C = Algebraic!(short, int, long, float, double);
static assert(!C.hasFixedSize);
assert(C(1) != C(2.0));
assert(C(1) == C(1.0));
import nxt.fixed_array : MutableStringN;
alias String15 = MutableStringN!(15);

String15 s;
String15 t = s;
assert(t == s);

alias V = Algebraic!(String15, string);
V v = String15("first");
assert(v.peek!String15);
assert(!v.peek!string);

v = String15("second");
assert(v.peek!String15);
assert(!v.peek!string);

v = "third";
assert(!v.peek!String15);
assert(v.peek!string);

auto w = v;
assert(v == w);
w.clear();
assert(!v.isNull);
assert(w.isNull);
w = v;
assert(!w.isNull);

v = V.init;
assert(v == V.init);

check default values

import nxt.fixed_array : MutableStringN;
alias String15 = MutableStringN!(15);

alias V = Algebraic!(String15, string);
V _;
assert(_._tix == V.Ix.init);
assert(V.init._tix == V.Ix.init);

// TODO: import nxt.bit_traits : isInitAllZeroBits;
// TODO: static assert(isInitAllZeroBits!(V));

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